1. Field of the Invention
This invention relates to a compact photographic zoom lens of high magnification for a 35 mm film still camera.
2. Description of the Prior Art
A zoom lens can freely change the magnification of an object without interchanging the lens. That is, it can photograph an object while changing the object to a predetermined dimension on the spot in accordance with the photographer's intention. Therefore, zoom lenses have become more and more widely used. Usually, zoom lenses having a magnification change ratio of 5 to 10 times are used with 8 mm cinecameras, and zoom lenses having a magnification change ratio of 10 to 30 times are used with television cameras. In the case of still cameras having great picture plane dimensions and chiefly photographing stationary objects, as compared with 8 mm cameras or television cameras having small picture dimensions and chiefly photographing moving objects, an optically higher performance is required and it is therefore difficult to obtain zoom lenses of a great magnification change ratio. This is because it is difficult to accomplish well correction of aberrations in zoom lenses of great magnification change ratio for still cameras. Particularly, it is often the case that the quality of photographs by a zoom lens in which only the magnification change ratio is made great, is remarkably lower than the quality of photographs by a lens of a single focal length, and an effort to make the zoom lens compact in order to improve the operability thereof often results in a disadvantage that aberration fluctuation becomes great. Compact photographic zoom lenses of high magnification improved to overcome the above-noted disadvantages have been proposed in U.S. Pat. No. 4,189,213 and Japanese Patent Publication No. 2941/1971.